Low Temperature Plasma‐Based Sterilization: Overview and State‐of‐the‐Art

Abstract

Summary: Low temperature, high pressure, non‐equilibrium plasmas are now routinely used in several material processing applications, and in some cases are competing with low pressure plasmas in areas where these have historically been dominant. Etching and deposition are examples of such applications. Amongst the novel applications of non‐equilibrium plasmas, biomedical applications such as electrosurgery, surface modification of biocompatible materials, and the sterilization of heat‐sensitive medical tools are particularly interesting. In this paper, first a brief overview of recent research on reduced‐pressure plasma‐based sterilization/decontamination methods is given. Then a detailed review and discussion on the effects of atmospheric pressure non‐equilibrium plasmas on the cells of bacteria is presented. This includes the evaluation of the inactivation kinetics and the roles of the various plasma agents in the inactivation process. Measurements of the plasma temperature, the UV emission, and concentrations of various reactive species for the case of air plasma are presented. Plasma sub‐lethal effects are also briefly discussed, and the prospects of the use of “cold” plasmas in the biomedical field are outlined. magnified image

Structure–property and composition–property relationships for poly(ethylene terephthalate) surfaces modified by helium plasma-based ion implantation

“…However, it absorbs at  = 310 nm [16], leading to molecular scission [17]. (UV radiation is known to be present in low temperature He plasma [18]). Discoloration of PET was already observed on UV-treatment -where the photodegradation was attributed to the ester carbonyl group as chromophore [19] -and on ion beam treatment [20].…”

Protein destruction by a helium atmospheric pressure glow discharge: Capability and mechanisms

“…Phys. 101, 074701 ͑2007͒ modes of the microorganism resistance to plasma treatment can be a result of many different factors including the cell wall, 4,6 phase of cell growth, 12 and cell stacking. 17 To understand the factors that contribute to the essentially biphasic kinetics of plasma protein reduction, we took fluorescence images of the FITC-labeled protein sample after different plasma treatment times.…”

“…So far, the bio-decontamination effect of APGD has been examined almost exclusively for microbial inactivation, in which case they have been shown comprehensively to be capable of inactivating wide-ranging microorganisms including the vegetative cells of yeast and bacteria, viruses, bacterial spores, and even biofilm-forming bacteria. [4][5][6][7][8] A great deal has been learned about how APGD inactivation depends on the plasma operating conditions 9,10 and the physiology of the microbial population. 11,12 These studies have helped establish convincingly the microbiocidal capability of APGD.…”

“…Today, atmospheric pressure glow discharges are widely regarded as one of the most exciting technology platforms that is likely to impact profoundly on the bio-decontamination practice and policy in both the healthcare service and the food industry. 4,8 Much less known is the capability of APGD for inactivation and destruction of proteinaceous matters, 13,14 even though surgical instruments are usually contaminated by both bacteria and proteins. This lack of understanding is of great concern, given the considerable risks of prion contamination of surgical instruments to many patients, particularly those who require neurosurgery.…”

Micro-Biocidal Activity of Yeast Cells by Needle Plasma Irradiation at Atmospheric Pressure

“…Low-temperature atmospheric-pressure plasma has attracted much attention for the bacterial inactivation, organics decomposition and gas analysis [1][2][3][4][5][6][7][8]. This plasma is expensively known as "touchable plasma" whose electrical temperature is high and gas temperature is low [2,7].…”